[SalesForce] how to create the url in lightning for vf page

This looks to be a namespace issue similar to the one described here - currently in review.

It can be reproduced using these steps as mentioned on the link

• Create an namespace on your Developer Org and a Managed Package
• Add the two Visualforce Pages to the package and upload it copying the link
• Log into another organization and install the package.
• Override the Account View with TestPage1 and then switch to Lightning Experience.
• Navigate to any Account page and click on either the A href link or OutputLink, clicking OutputLink will work as expected maintaining the correct namespace, clicking on A href link will navigate to your default org namespace which results in either URL "No Longer Exists" or "Page namespace__TestPage1 does not exist". (Behavior varies on how the page will display)

The suggested workaround is not ideal, but it works

1) Right click on the link and select "Open Link in New Tab";
2) Disable Lightning Experience;
3) Change the tag references to make use of the Visualforce tag

I would recommend that you add conditional code at the top of your page that determines what environment the User is currently in, then either displays the page using the Lightning experience where it puts the page in a Lightning I-Frame or if the user is in Classic mode, directly displays it without the I-frame. See Sharing Visualforce Pages Between Classic and Lightning Experience which contains the code for how to do this.